Treatment of footwear

ABSTRACT

Footwear treatment system comprising a conveyor made up of a plurality of chain sections each to carry a batch of footwear to be treated. Chain passes through modular footwear treatment zones in which the footwear is first heat set and then dried by vacuum. Timed meter steps conveyed to transfer batches from zone to zone at equal intervals.

United States Patent 1191 Freeman June 19, 1973 TREATMENT OF FOOTWEAR 3,533,117 10 1970 Dinolfo et al .1 12 1 A [76] Inventor: Alfred Freeman, 94 Orlingbury Road lsham England Primary Examiner-Patrick D. Lawson [22] Filed: July 2, 1971 Attorney-Larson, Taylor and Hinds [211 App]. N0.: 159,247

57 BSTRA T [30] Foreign Application Priority Data 1 A July 4, Great Britain Footwear treatment system comprising a conveyor 7 made up of a plurality of chain sections each to carry [52] US. Cl 12/1 A a batch f f t to be treated Chain passes through 1 E modular footwear treatment zones in which the foot- [58] Field of Search 12/1 R, l A wear is fi t heat Set and then dried by vacuum Timed meter steps conveyed to transfer batches from zone to References Cited zone at equal intervals.

UNITED STATES PATENTS 3,089,162 5/1963 Richter et al. 12/1 A 12 Claims, 5 Drawing Figures PAIENIIZU mu sum SHEEIIUFS PATEN TED MI 1 9 SHEEI 2 HF 1 TREATMENT OF FOOTWEAR This invention is concerned with the treatment of articles of footwear. Where used in this specification, the term footwear" is intended to include both complete articles of footwear and components thereof at any convenient stage of manufacture, preparation or aftertreatment.

The treatment of footwear during manufacture includes the operations of adding and subtracting, water, stress relieving, the removal of solvents in the cements, puffs, counters etc.

One conventional footwear treatment method is heat setting". In this process the articles to be treated are mounted on lasts, and advanced through a chamber in which they are subjected to the action of hot moist or hot dry air, for a predetermined period, say, 6 minutes. During this period the leather becomes tensioned over the lasts and each shoe upper assumes the shape of the last on which it is mounted.

Following such a heat setting operation, the articles may be subjected to sub-atmospheric pressure to cause accelerated evaporation therefrom of liquids (including not only moisture, but also cement, solvents, e.g. acetone, etc.) This invention is concerned, in particular, with a footwear treatment system of this kind in which the articles travel successively through a plurality of treatment zones including at least a heat setting (or equivalent) zone followed by a vacuum treatment zone (i.e. in which the footwear is treated at subatmospheric pressure). A system of this kind will hereinafter be denoted a treatment system of the kind referred to.

An object of this invention is to provide improvements in such a system, designed to ensure identical treatment conditions for each article of footwear travelling therethrough.

Broadly considered, according to the invention,in a treatment system of the kind referred to, the articles are arranged to travel through the system in batches, each batch being treated for the same pre-determined period at each treatment zone so that all the articles received identical treatment. Thus, each batch is treated as a whole in each zone before passing on to the next.

Conveniently, the articles are batched before entering the system; each batch is then delivered first to a heat setting chamber or zone where it remains for a predetermined period. At the end of this period, the whole batch is transferred to a vacuum chamber for treatment at sub-atmospheric pressure for a further predetermined period before leaving the system.

The system preferably includes conveyor means adapted to carry a plufality of batches of footwear articles to be treated, and arranged to/move the batches stepwise through the system in unison, the interval between successive steps determining the treatment period of the batches at each treatment zone.

In one embodiment, the articles of footwear may be conveyed on individual carriers up to and through the system. In this event, batching of the articles may be accomplished by arranging to group the carriers into a batch before they enter the heat setting zone and by providing means to move the group as a whole through the system.

In this case, the carriers may, for example, be of the form disclosed in my prior U.K. Letters Patent No.: 1,076,412 dated Aug. 13, I965.

The means for moving the batches of carriers may comprise a slide which is adapted to be reciprocated in the direction of carrier travel by a distance equal to the spacing of two successive zones in the system, and is provided with spring-loaded catches to engage the rearmost carrier in each group and move this carrier, and preceding carriers by abutment, to the next stage in the system; return reciprocation of the slide will deflect the catches against their spring action so that they idly return to their starting positions.

In accordance with a different embodiment of the invention, the conveyor means may be incorporated in an independent and self-contained unit for the batch treatment of articles of footwear. Conveniently, in this event, each batch of articles to be treated is transported through the unit on its own individual carrier.

The unit may itself be of modular construction and comprise: a plurality of standard-sized compartments, through which the carriers successively travel in use, one of the compartments being constructed as a vacuum chamber in which the articles on the carriers can be subjected to sub-atmospheric pressure to cause accelerated evaporation of moisture therefrom; means to produce a circulation of hot, moist or hot dry air in some, at least, of the other compartments in advance of the vacuum compartment to heat-set articles of footwear; and means for simultaneously transferring each carrier in the unit from the compartment it occupies at the time, to the next following compartment in the direction of the carrier travel through the unit.

Preferably however, the conveyor means of the system comprise an endless chain conveyor made up of a plurality of equal-length chain sections joined end to end, each adapted to carry a batch of footwear articles, and a plurality of footwear-treatment zones are arranged around the system with the conveyor chain extending therethrough, each zone being of a length to accommodate one batch of articles carried by a chain section, the chain being intermittently movable in steps equal to the length of a chain section to transfer one batch of articles into and one batch from each zone at each step.

In order that the invention may be more clearly understood and readily carried into practice, reference will now be made to the accompanying drawings which illustrate one embodiment thereof, by way of example, and in which:

FIG. 1 is a side view of a footwear-treatment unit constructed according to the invention,

FIG. 2 is a plan view corresponding to FIG. 1,

FIG. 3 is a perspective view in the direction of arrow A in FIG. 1 showing a part of the unit,

FIG. 4 is a detail view, partly in section, of the part of the unit indicated at B in FIG. 1, and,

FIG. 5 is a view, partly in section, on arrow C in FIG. 2, showing a part of the unit at the side remote from the view of FIG. 1.

Referring first to FIGS. 1 and 2, the unit is of modular construction and provides eight treatment zones T arranged in two side-by-side rows to provide appropriate conditions for the particular footwear treatment required. The zones T are indicated by chain lines in FIG. 2. In use, the batches of footwear articles to be treated travel stepwise from zone to zone along first one row and then the other as will be described. Of course, additional modules can be incorporated to provide a longer treatment path if appropriate.

As indicated in FIG. 2, one of the zones forms a loading station S followed, in the direction of movement of the footwear (indicated by the arrow), by six zones which communicate one with the other and in which the footwear is subjected to the action of hot, moistureladen air as will be explained. The moisture is imparted to the air by a heat setter which forms the fourth of these zones and is indicated at I-IS. This apparatus will be more specifically described later with reference to FIG. 5.

After the moisture treatment, the footwear enters a vacuum chamber V in which it is subjected to subatmospheric pressure to remove moisture etc., therefrom.

As mentioned above, the moisture treatment zones communicate with one another, being enclosed by a metal casing 1, made up ofa plurality of casing sections joined together so as to form a substantially air-tight enclosure. Inspection panels P are provided in the casing. The entrance to the said enclosure is by way of a door between the casing 1 and the loading station S. At the end of the enclosure is the vacuum chamber V, casing 1 simply terminating adjacent the relevant end of the vacuum chamber. Although this leaves a slight air gap there is, in practice, no significant loss of moistureladen air therethrough.

The casing 1 and chamber V are supported by upstanding frames 2 which are of inverted U shape.

Footwear articles to be treated in the unit are transported in batches on an endless chain conveyor 3. The form of the conveyor dhain is more specifically indicated in FIG. 4. It is enclosed Within a rectangular section trackway 4 having a central longitudinal slot 5 in its upper face. The chain itself is divided into sections, each of a length equal to the length of one of the zones of the unit and in use carries one batch of articles. Each section comprises a plurality of upstanding rods 6 to carry lasts L (FIG. 3) for, in this case, shoe uppers to be treated in the unit. Intermediate the rods 6 are similar rods 7 of smaller height which also carries lasts, but at a lower level. This alternate high/low arrangement allows an increased number of lasts to be carried per unit chain length.

Each rod 6 is mounted at its lower end on a horizontal plate 8 which (except at the ends of a chain section) is pivoted at each end to a similar plate 9 carrying one of the rods 7. The pivot is formed by an upstanding spindle 10 which carries a horizontal wheel 11 at its lower end and at its upper end is connected by a plate 12 to a similar spindle/wheel arrangement at the opposite side of the rod 6. Similarly, each plate 9 carries a pair of vertical wheels 13 on a spindle 14 welded thereto. The horizontal wheels run on the sides of the trackway and the vertical wheels on the base.

As can be seen from FIG. 2, the trackway is arranged so that the chain travels along two parallel runs connected at opposite ends by curved runs,.each of the parallel runs passing through one row of treatment zones T. The drive for the chain is by means of a motor 16 which, through a gearbox 17, drives a vertical spindle 18 carrying a sprocket 19 at its upper end. The inside wall of the trackway 4 is cut away in the region of this sprocket so that the teeth of the latter can engage and drive on the spindles 10 and rods 6, 7 of the chain.

Motor 16 is controlled by a timer 20 of conventional form which is wired into its electrical power supply leads. The timer is constructed to intermittently activate the motor and allow it to run for a length of time sufficient to move each of the chain sections by an amount equal to the length of one zone T. In other words, each time the motor is switched on by the timer, each chain section moves from the zone it occupies at that time into the next zone. Between each drive period is a dwell period during which the articles of footwear receive treatment. The timer can be adjusted to vary the duration of this dwell period in accordance with treatment requirements.

Referring again to FIGS. 1 and 2, the vacuum chamber V of the unit comprises a rectangular section tubular casing 21 of sufficient thickness to withstand internal pressures of the order of 28 inches of mercury. Thus, the walls of this part of the unit must be substantially thicker than the thickness of casing 1. Each end of the vacuum chamber is closed by a verticallyslidable door 22 which is received in inwardly-facing channel-section guides 23 (FIG. 3). It will be noted that the section of the trackway 4 inside the chamber is separate from the remainder to allow the doors to close. Each door is arranged to be moved by a pneumatic piston/cylinder unit 24, between a down, closed position during which the articles of footwear are sealed inside the chamber for treatment and an open position (FIG.

3) during transfer of the footwear articles to and from the chamber. Each unit 24 is mounted with its axis vertical on the horizontal limb on an inverted U-shaped support frame 25 so that its piston rod connects with the associated door adjacent the centre of its width.

The lower edge of each door has a cut-out 220 (FIG. 3) shaped and positioned to cooperate with the U- shaped connecting limb 15 (FIG. 4) between adjacent sections of the chain. A rubber sealing pad 26 is secured to the cut-out to ensure a good vacuum-tight seal. For the same reason, rubber sealing strips 27, 28 are provided all around each open end of the chamber.

Numeral 29 indicates a pair of conventional air heaters inside the vacuum chamber.

The door (referred to above) at the entrance to the moisture laden-air enclosure is of similar construction to the vacuum chamber doors and is denoted by similar reference numerals.

A motor driven-vacuum pump 30 is connected to the chamber V through a vacuum gauge 31 to evacuate the chamber at appropriate times. A moisture extractor (not shown) is included in the pump. The chamber also has a vent 32 to atmosphere which is controlled by a solenoid valve 33.

The unit is controlled by an appropriate electrical circuit from the timer 20, the circuit being arranged to operate on the following cycle (starting from the condition in which the doors 22 have just opened) 1. Timer 20 activates motor 16 to move the chain by an amount equal to the length of one zone T.

2. Timer stops motor 16, closes valve 33 and operates units 24 to close the doors 22.

3. Pump 30 operates to evacuate the vacuum chamher.

4. At the end of the dell period set by the timer, valve 33 opens and the pistons of units 24 are retracted to open the doors.

The sequence then repeats.

Referring now to FIG. 5, the heat setter I-IS will be described.

Beneath the floor F of the relevant module is an auxilliary enclosure 34 which is divided longitudinally by a partition 35 (also indicated in FIG. chamber 34a and a rear chamber 34b. In addition, partitions 36, 37 extend across chamber 34a. The partitions 36 are full length and divide chamber 340 into three separate sections, the two end sections communicating with the rear chamber 34b. The right hand end section also includes a water tank 38 controlled by a ball valve 39. Intermediate partitions 37 is a fan 40, which also communicates with chamber 34b. Heater coils 41 are provided between each pair of partitions 36, 37.

In use, fan 40 draws air into chamber 34a through inlets 42 and over the heater coils which elevate its temperature. The fan then directs the air through to the rear chamber 34b, from where it leaves the enclosure 34 through outlets 43. During this movement the air picks up water from tank 40 and becomes moisture saturated. The air turbulance produced by the fan 38 and by the operation of the unit causes the air to circulate in the six moisture-treatment zones of the unit.

A reading of the air temperature in these zones is provided by a thermometer 43 on top of the heat setter.

It is to be noted that this form of heat setter is described and claim in U.S. Pat. No. 3,579,849.

In use, starting from the position of FIG. 1, an operative standing at the loading station S loads a batch of articles of footwear on to the rods 6, 7 of the conveyor on the particular chain section presented to him. The dwell period of the timer is selected to allow him sufficient time to do this. The control circuit then commences the cycle described above so that that batch of shoes is conveyed into the first part of the moisture treatment enclosure. Now the operative is then presented with a chain sedtion carrying articles which have just emerged from the vacuum chamber; he removes them and replaces them with fresh footwear articles to be treated in the dwell period of the timer and the cycle commences.

Thus, each batch of articles carried by a chain section passes successively through all six moisture treatment zones and receives an appropriate treatment in the hot, moisture-laden air produced by the heat setter HS. In turn each batch then enters the vacuum chamber V. The articles are hot at this time and the heaters inside the chamber help to maintain the heat level therein; the reduced pressure to which the articles are subjected in the chamber causes moisture, solvents etc., to evaporate from the articles to dry the same. The unit thereby provides a complete treatment process, the articles leaving the chamber being fully heat set and dry.

I claim:

1. A footwear treatment system of the kind in which articles of footwear to be treated travel through a plurality of treatment zones including at least one heat treatment zone followed by a vacuum treatment zone, wherein the articles are arranged to travel through the system in batches, each batch being treated for the same predetermined period at each treatment zone so that all the articles receive identical treatment.

2. A system according to claim 1, which includes conveyor means adapted to carry a plurality of batches of footwear articles to be treated, and arranged to move the batches stepwise through the system in unison, the interval between successive steps determining the treatment period of the batches at each treatment zone.

2) into a front chain section and to 3. A system according to claim 2, wherein the conveyor means comprise an endless chain conveyor made up of a plurality of equal-length chain sections joined end to end, each section being adapted to carry a batch/of footwear articles, and wherein a plurality of footwear-treatment zones are arranged around the system with the conveyor chain extending therethrough, each zone being of a length to accommodate one batch of articles carried by a chain section, and the chain being intermittently movable in steps equal to the length of a chain section to transfer one batch of articles into and one batch from each zone at each step.

4. A system according to claim 3, wherein each conveyor chain section comprises a plurality of wheeled chain links carrying upstanding rods to support footwear articles to be treated, the chain running in an endless channel-form trackway, and being intermittently conveyed along the latter by a motor-driven sprocket arranged in driving engagement with the chain sections.

5. A system according to claim 4 wherein the motor driving the chain sprocket is controlled by a timer which is adjustable to vary the interval between each movement of the chain.

6. A system according to claim 4, wherein alternate rods of the chain sections are shorter than the intervening rods so that a batch of last-mounted footwear articles can be carried in closely-spaced relationship on each section.

7. A system according to claim 3, comprising a footwear treatment unit which is of modular construction and provides a succession of equal-size zones through which the conveyor chain successively travels, the length of each zone being equal to the length of each the amount through which the chain moves at each step.

8. A system according to claim 7,. wherein the zones are defined by a casing which completely encloses the chain with the exception of one zone in which the chain is exposed to allow the loading and] unloading of articles of footwear.

9. A system according to claim 8, wherein the loading and unloading zone is followed, in the direction of conveyor travel, by a plurality of communicating zones in which a circulation of hot, moisture-laden air is provided to heat set the articles travelling therethrough, these zones being followed by a vacuum-treatment zone immediately in advance of the loading and unloading zone, in which the articles are exposed to sub atmospheric pressure to cause evaporation of moisture, solvents and the like therefrom.

10. A system according to claim 9, wherein the circulation of hot, moisture-laden air in the relevant zones is produced by a heat setting apparatus incorporated in one of the latter, this apparatus comprising:means for producing a circulation of air; means for heating the air; and an evaporation device from which water is picked up by the circulating air.

1 1. A system according to claim 9, wherein the vacuum-treatment zone is defined by a vacuum chamber comprising: an open-ended casing having a length of conveyor trackway extending therethrough; doors adapted to seal the ends of the chamber in pressuretight fashion at appropriate times; and air extraction means connectible to the interior of the sealed chamher to evacuate the same.

12. A system according to claim 11, wherein the doors of the chamber are verticallyslidable to open and close the ends of the latter, and wherein the sec- 

1. A footwear treatment system of the kind in which articles of footwear to be treated travel through a plurality of treatment zones including at least one heat treatment zone followed by a vacuum treatment zone, wherein the articles are arranged to travel through the system in batches, each batch being treated for the same predetermined period at each treatment zone so that all the articles receive identical treatment.
 2. A system according to claim 1, which includes conveyor means adapted to carry a plurality of batches of footwear articles to be treated, and arranged to move the batches stepwise through the system in unison, the interval between successive steps determining the treatment period of the batches at each treatment zone.
 3. A system according to claim 2, wherein the conveyor means comprise an endless chain conveyor made up of a plurality of equal-length chain sections joined end to end, each section being adapted to carry a batch/of footwear articles, and wherein a plurality of footwear-treatment zones are arranged around the system with the conveyor chain extending therethrough, each zone being of a length to accommodate one batch of articles carried by a chain section, and the chain being intermittently movable in steps equal to the length of a chain section to transfer one batch of articles into and one batch from each zone at each step.
 4. A system according to claim 3, wherein each conveyor chain section comprises a plurality of wheeled chain links carrying upstanding rods to support footwear articles to be treated, the chain running in an endless channel-form trackway, and being intermittently conveyed along the latter by a motor-driven sprocket arranged in driving engagement with the chain sections.
 5. A system according to claim 4, wherein the motor driving the chain sprocket is controlled by a timer which is adjustable to vary the interval between each movement of the chain.
 6. A system according to claim 4, wherein alternate rods of the chain sections are shorter than the intervening rods so that a batch of last-mounted footwear articles can be carried in closely-spaced relationship on each section.
 7. A system according to claim 3, comprising a footwear treatment unit which is of modular construction and provides a succession of equal-size zones through which the conveyor chain successively travels, the length of each zone being equal to the length of each chain section and to the amount through which the chain moves at each step.
 8. A system according to claim 7, wherein the zones are defined by a casing which completely encloses the chain with the exception of one zone in which the chain is exposed to allow the loading and unloading of articles of footwear.
 9. A system according to claim 8, wherein the loading and unloading zone is followed, in the direction of conveyor travel, by a plurality of communicaTing zones in which a circulation of hot, moisture-laden air is provided to heat set the articles travelling therethrough, these zones being followed by a vacuum-treatment zone immediately in advance of the loading and unloading zone, in which the articles are exposed to subatmospheric pressure to cause evaporation of moisture, solvents and the like therefrom.
 10. A system according to claim 9, wherein the circulation of hot, moisture-laden air in the relevant zones is produced by a heat setting apparatus incorporated in one of the latter, this apparatus comprising:means for producing a circulation of air; means for heating the air; and an evaporation device from which water is picked up by the circulating air.
 11. A system according to claim 9, wherein the vacuum-treatment zone is defined by a vacuum chamber comprising: an open-ended casing having a length of conveyor trackway extending therethrough; doors adapted to seal the ends of the chamber in pressure-tight fashion at appropriate times; and air extraction means connectible to the interior of the sealed chamber to evacuate the same.
 12. A system according to claim 11, wherein the doors of the chamber are vertically-slidable to open and close the ends of the latter, and wherein the sections of the conveyor chain are joined by thin connecting elements onto which the doors of the vacuum chamber seal. 